In a large pot, Dutch Oven, or deep cast iron skillet make a brown roux by cooking the oil and flour on medium high heat, stirring constantly. About 5 minutes. You don’t want the roux too dark because it will continue to cook in the next step.

When the roux is the color you’d like, add the chopped onions, celery, bell pepper, carrots, and garlic. Cook until the vegetables are tender, about 8 minutes. Add the tomatoes plus juice and cook in the vegetable mixture for a few minutes.

Next, add 1 qt of warm stock and Worcestershire sauce. Season with the Tony Chachere’s and bay leaf. Bring to a boil, then lower to a simmer. Simmer for about 30 minutes, adding more liquid if needed.

Add in ½ cup of the green onions, the parsley, and lemon juice. Taste the sauce for seasoning and adjust if needed. Gently add the fish and/or shrimp and do not boil or stir. Simmer fish covered for about 10-15 minutes, depending on thickness.

Serve the Courtbouillon over rice and garnish with reserved green onion and a squeeze of lemon.